The Dale class were a class of replenishment oilers taken up for service with the Royal Fleet Auxiliary, supporting the Royal Navy during the inter-war period. The went on to see action during the Second World War.

The Darkdale became the first British ship sunk south of the equator during WW2 when she was torpedoed by the German submarine U-68 as she lay at anchor off Jamestown in the early hours of 22 October 1941.

Now oil is gradually seeping from the hull into the 40-metre deep waters of James Bay and the UK Defence Equipment and Support (DE&S) survey will decide what, if any, action is needed to prevent the Darkdale becoming an environmental hazard to an island where tourism is on the increase.

Matt Skelhorn, the team's wreck research analyst, said: “St Helena was an important stopping-off point for ships passing to South East Asia, particularly with war taking place in the Mediterranean.

”The guys who will be leading the survey are very experienced. I don't think Darkdale will pose a huge technical challenge in surveying the wreck; it's just a matter of physically getting out there."

She blew up, broke in half and sank. The bow section turned turtle and the stern section is on its side. We don't know how much oil is on board and until we start doing an in-depth survey of her we cannot be certain.